Semiconductor device manufacturing device and manufacturing method

This application is a 371 application of the International PCT application serial no. PCT/JP2020/046618, filed on Dec. 14, 2020. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.

The present specification discloses a manufacturing device and a manufacturing method in which a semiconductor device is manufactured with one or more chips bonded on a substrate.

In the related art, a manufacturing device for installing one or more chips on a substrate to manufacture a semiconductor device is known. Such a manufacturing device has an installing tool that sucks and holds a chip, and when the chip is disposed on the substrate, the installing tool is moved such that the chip is disposed in a desired position. Further, when the chip is disposed on the substrate, it is also important that a bonding surface of the chip facing the substrate be parallel to an installing surface of the substrate. If the chip is tilted with respect to the installing surface, the chip causes an installing defect with respect to the substrate. For example, an electrical bonding defect may occur between a bump electrode of the chip and an electrode of the substrate.

Here, in Patent Literature 1, a technique in which, when an IC component is temporarily pressure-bonded to an electrode provided in a flat panel display, the amount of misalignment of the mounted IC component with respect to the electrode is detected by a camera, and in a case in which the amount of misalignment is not appropriate, the amount of misalignment is fed back to correct a temporary pressure bonding operation of a next IC component is disclosed. Further, in Patent Literature 1, a technique in which a bonding state between a bump and an electrode is detected, and in a case in which the bonding state is not appropriate, a warning is output assuming that a degree of parallelization between the IC component and the display exceeds the allowable range is also disclosed. According to the technique of Patent Literature 1, the amount of misalignment is appropriately detected and fed back, and thus positioning accuracy of the IC component can be kept high.

Japanese Patent No. 3323395

However, in the technique of Patent Literature 1, the degree of parallelization is determined as only good or bad, and no feedback is given. Therefore, in the related art such as Patent Literature 1, the degree of parallelization of the chip with respect to the substrate cannot be kept high.

Therefore, the present specification discloses a semiconductor device manufacturing device capable of further improving the degree of parallelization of the chip with respect to the substrate.

A semiconductor device manufacturing device disclosed in the present specification includes a stage that has a loading surface on which a substrate is loaded; an installing head that has a chip holding surface for holding a chip and disposes the chip on the substrate loaded on the stage; a measuring mechanism that measures a tilt angle of the chip loaded on an installing surface of the substrate by the installing head with respect to the installing surface as a detection tilt angle; a holding surface adjusting mechanism that changes a holding surface tilt angle which is a tilt angle of the chip holding surface with respect to the loading surface; and a controller that calculates a correction amount of the holding surface tilt angle on the basis of the detection tilt angle and changes the holding surface tilt angle by the holding surface adjusting mechanism according to the correction amount calculated.

In this case, the controller may store a plurality of the detection tilt angles measured in the past, and the controller may obtain a basic tilt angle by removing an influence of correction of the holding surface tilt angle from each of the plurality of detection tilt angles and may change a calculation policy of the correction amount according to a change tendency of the basic tilt angle between the substrates.

Further, in a case in which a variation of the basic tilt angle between the substrates is equal to or less than a specified allowable value, the controller may calculate a value to cancel the detection tilt angle obtained for a nearest substrate as the correction amount.

Further, in a case in which the basic tilt angle changes between the substrates with a predetermined regularity, the controller may estimate a basic tilt angle of a next substrate according to the regularity and may calculate a value to cancel the basic tilt angle as the correction amount.

Further, in a case in which the basic tilt angle changes randomly between the substrates, the controller may estimate a representative value of a plurality of the basic tilt angles obtained for a plurality of the substrates as a basic tilt angle of a next substrate and may calculate a value to cancel the basic tilt angle as the correction amount.

Further, in a case in which the detection tilt angle is obtained for each of a plurality of chips loaded on one substrate, the controller may treat a representative value of a plurality of the detection tilt angles obtained for the plurality of chips as the detection tilt angle of the one substrate.

Further, in a case in which the detection tilt angle is obtained for each of a plurality of chips loaded on one substrate, the controller may generate a map in which a correspondence between a position of each chip in the substrate and the detection tilt angle of each chip is recorded and may calculate the correction amount for each chip position on the basis of the map.

Further, the installing head may have an installing tool that includes the chip holding surface and a spherical air bearing that holds the installing tool, the spherical air bearing may be capable of switching between a free state in which the installing tool is held with its swinging allowed and a locked state in which the installing tool is held with its swinging hindered, and the holding surface adjusting mechanism may have a tilt plate with which the chip holding surface is brought into contact, and a plurality of support columns that supports the tilt plate and advances and retreats independently of each other to arbitrarily change an angle of the tilt plate.

A semiconductor device manufacturing method disclosed in the present specification includes a bonding step of holding a chip with a chip holding surface of an installing tool and moving the installing tool to load the chip on an installing surface of a substrate loaded on an loading surface of a stage; a measurement step of measuring a tilt angle between an upper surface of the chip loaded on the installing surface and the installing surface as a detection tilt angle; a correction amount calculation step of calculating a correction amount of a holding surface tilt angle, which is a tilt angle of the chip holding surface with respect to the stage, on the basis of the detection tilt angle; and a correction step of changing the holding surface tilt angle according to the correction amount by a holding surface adjusting mechanism that changes the holding surface tilt angle.

According to the technique disclosed in the present specification, the degree of parallelization of the chip with respect to the substrate can be further improved.

Hereinafter, a configuration of a semiconductor device manufacturing devicewill be described with reference to the drawings.is a conceptual view showing a configuration of the manufacturing device. The manufacturing deviceis a device that manufactures a semiconductor device by installing a chip, which is an electronic component, on a substratein a face-down state. The manufacturing deviceincludes a stageon which the substrateis loaded, an installing headthat installs the chipon the substrate, a measuring mechanismthat measures a degree of parallelization of the installed chipwith respect to the substrate, a holding surface adjusting mechanismthat changes a tilt of a chip holding surfaceof the installing head, and a controllerthat controls the drive of the installing heador the holding surface adjusting mechanism.

The stagecan suck and hold the substrate, and a heater (not shown) for heating the substrateis installed inside the stage. The heating and suction of the stageare controlled by the controller, which will be described later. An upper surface of the stagefunctions as a loading surfaceon which the substrateis loaded. The stageof the present example is a fixed stage of which vertical and horizontal positions do not change, but in some cases, the stagemay be movable in at least one of a vertical direction and a horizontal direction.

The installing headincludes an installing toolthat sucks and holds the chip, and a moving mechanism (not shown) that moves the installing toolin the horizontal direction and the vertical direction. The installing toolis disposed to face the substrate, and a tip end surface thereof functions as the chip holding surfacethat sucks and holds the chip. Further, a heater (not shown) for heating the held chipis built in the installing tool. The installing toolsucks and holds the chipwith the chip holding surface, loads the chipon a surface (hereinafter referred to as an “installing surface”) of the substrate, and heats and pressurizes the chipto bond the chipto the substrate.

Further, the installing headof the present example has a spherical air bearing. The spherical air bearinghas a fixed portionand a movable portion, one of the fixed portionand the movable portionhas a concave hemispherical surface, and the other has a convex hemispherical surface that slides inside the concave hemispherical surface. Swinging of the movable portionwith respect to the fixed portionis controlled by sucking or supplying air from or to the gap between the two portions. That is, when air is supplied to the gap, three-dimensional swinging of the movable portionwith respect to the fixed portionis allowed, and when air is sucked from the gap, three-dimensional swinging of the movable portionwith respect to the fixed portionis hindered. In the following, a state in which air is supplied and the swinging of the movable portionis allowed is referred to as a “free state,” and a state in which air is sucked and the swinging of the movable portionis hindered is referred to as a “locked state.” In the present example, the movable portionof the spherical air bearingis attached to the installing tool, and the fixed portionis attached to a main bodyof the installing head. In this case, by pressing the chip holding surfaceagainst a desired surface after the spherical air bearingis made to be in a free state, it is possible to make the chip holding surfaceparallel to the desired surface. In other words, by providing the spherical air bearing, it is possible to change swinging of the installing toolwith respect to the main bodyand a tilt angle (hereinafter referred to as a “holding surface tilt angle Sb”) of the chip holding surfacewith respect to the loading surface.

When the chipis installed on the substrate, the installing toolis lowered toward the substratein a state in which the chipis held with the chip holding surface, and the chipis loaded on the installing surfaceof the substrate. Then, the chipis heated and pressurized in that state, and thus a bump(see) provided on a bottom surface of the chipis welded to an electrode(see) of the substrate.

The measuring mechanismmeasures an installed state of the chipon the substrate, particularly, a tilt angle of the chipwith respect to the installing surface. The measured tilt angle of the chipis transmitted to the controlleras a detection tilt angle Sd. The controllercorrects the holding surface tilt angle Sb on the basis of the obtained detection tilt angle Sd, which will be described later.

The method for measuring the detection tilt angle Sd is not particularly limited, and for example, a contact-type tilt sensor, a non-contact-type distance sensor, or the like may be used for measurement. For example, in a case in which a laser measuring devicethat measures a distance in a non-contact manner is used, the laser measuring devicemeasures distances to a plurality of substrate-side measuring points set on the installing surfaceand distances to a plurality of chip-side measuring points set on an upper surface of the chip. Then, the measuring mechanismcalculates a tilt angle of the installing surfaceon the basis of the distances to the plurality of substrate-side measuring points, calculates a tilt angle of the upper surface of the chipon the basis of the distances to the plurality of chip-side measuring points, and calculates the tilt angle of the chipwith respect to the installing surface, that is, the detection tilt angle Sd from the two tilt angles. The method for measuring the detection tilt angle Sd described here is an example and may be changed as appropriate.

The holding surface adjusting mechanismis a mechanism that adjusts the tilt angle of the chip holding surfacewith respect to the loading surface, that is, the holding surface tilt angle Sb. Specifically, the holding surface adjusting mechanismhas a tilt platewith which the chip holding surfaceis brought into contact. The tilt plateis supported by a plurality of support columnsthat can advance and retreat arbitrarily, and as shown in, it is possible to change a tilt angle of the tilt plateby adjusting protrusion amounts of arbitrary support columns. In a case in which the holding surface tilt angle Sb is adjusted, in advance, the support columnsare advanced and retreated to adjust the tilt plateto a desired tilt angle, and the installing toolis made to be in the free state in which the installing toolcan be swung with respect to the main body. In this state, the chip holding surfaceis brought into contact with the tilt plate, and the chip holding surfaceis made to conform with the tilt plate. Then, when the chip holding surfacecompletely conforms with the tilt plate, the installing toolis switched to a locked state in which the swinging of the installing toolis hindered. As a result, the holding surface tilt angle Sb is fixed at the same tilt angle as the tilt plate.

The controllercontrols the drive of each part of the manufacturing device. Specifically, the controllerdrives the installing headto execute a bonding process for bonding the chipto the substrate. Further, the controllerof the present example causes the holding surface adjusting mechanismto execute a correction process of the tilt of the chip holding surfaceas necessary, which will be described later. Such a controlleris a computer having a processorthat executes various operations and a memorythat stores data and programs.

Next, the correction process of the holding surface tilt angle Sb will be described. As shown in, the bumpthat functions as an electrode is formed on the bottom surface of the chip. When the chipis installed, the chipis loaded on the installing surfaceof the substratesuch that the bumpcomes into contact with the electrodeof the substrate, and then the chipis heated and pressurized by the installing tool. To ensure good installing quality, it is necessary to keep the chipand the installing surfaceparallel to each other during this pressurization and heating. In a case in which the chipand the installing surfaceare not parallel to each other, electrical bonding failure may occur between the bumpand the electrode.

Therefore, in the manufacturing deviceof the related art, the holding surface tilt angle Sb is adjusted such that the chip holding surfaceis parallel to the loading surfaceof the stageprior to the installing of the chip. Specifically, prior to the installing of the chip, the chip holding surfaceis pressed against the loading surfaceto make the installing toolconform with the loading surface.

However, since the manufacturing deviceof the related art merely adjusts the tilt of the installing toolwith respect to the stage, the degree of parallelization of the chipwith respect to the installing surfaceof the substrateis not sufficiently ensured. For example, as shown in, even though the chip holding surfaceis adjusted parallel to the loading surface, if the upper surface (the mounting surface) of the substrateis tilted with respect to a lower surface thereof due to a temperature change, a manufacturing error of the substrate, or the like, the chipis tilted with respect to the installing surface.

Therefore, in the present example, as necessary, the tilt angle of the chipwith respect to the installing surfaceis measured as the detection tilt angle Sd, and the holding surface tilt angle Sb is corrected to cancel the detection tilt angle Sd.is a conceptual view showing a state after correction.

In the present example, the measurement of the detection tilt angle Sd and the correction of the holding surface tilt angle Sb are performed for each substrate. This will be described with reference to.is a flowchart showing a flow in manufacturing a semiconductor device by the manufacturing deviceof the present example.

When a semiconductor device is manufactured, first, the substrateis transported to the stageand is loaded on the stage(S). Subsequently, the installing headis driven to bond the chipto the substrate. That is, the chipis loaded at a predetermined position on the substrateand is heated and pressurized (S). If the required number of chipscan be bonded to one substrate, the substrateafter the bonding is transported to the measuring mechanism.

The measuring mechanismmeasures the tilt angle of the chipwith respect to the installing surfaceas the detection tilt angle Sd and transmits the detection tilt angle Sd to the controller(S). Here, in a case in which a plurality of chipsis mounted on one substrate, the measuring mechanismmay measure the detection tilt angle Sd for only one representative chip(for example, a chipinstalled on a center of the substrateor the like) of the plurality of chips. Further, as another form, the measuring mechanismmay measure the detection tilt angle Sd for each of the plurality of chips. In this case, the controllertreats a representative value of a plurality of detection tilt angles Sd obtained for one substrateas the detection tilt angles Sd of the one substrate. Here, the “representative value” is a statistical value representing a central position of the distribution of data and is, for example, a mean, a median, or a mode. In any case, the controllerassociates one detection tilt angle Sd with one substrateand stores it in the memory.

If the detection tilt angle Sd is obtained, the controllerchecks the presence or absence of a next substrate(S). If there is no next substrateNo in S), the manufacturing process ends. On the other hand, in a case in which there is a next substrate(Yes in S), the controllerdetermines whether or not the holding surface tilt angle Sb needs to be corrected for the next substrateon the basis of the detection tilt angle Sd (S). Specifically, the controllercompares the obtained detection tilt angle Sd with a specified allowable tilt value. As a result of the comparison, in a case in which the detection tilt angle Sd is equal to or less than the allowable tilt value, it is determined that the current holding surface tilt angle Sb is appropriate and correction is not necessary (No in S). In this case, the controllerreturns to step Sand executes the next bonding process on the new substratewithout correcting the holding surface tilt angle Sb. On the other hand, when the detection tilt angle Sd exceeds the allowable tilt value, the controllerdetermines that the holding surface tilt angle Sb needs to be corrected (Yes in S). In this case, the controllerreduces a next detection tilt angle Sd and calculates a correction amount C such that the tilt angle of the chipapproaches the tilt angle of the installing surface(S). The calculation of the correction amount C will be described later.

If the correction amount C can be calculated, the controllercorrects the holding surface tilt angle Sb by the correction amount C using the holding surface adjusting mechanism(S). Specifically, the amount of the advancing and retreating of the support columnis adjusted to change the tilt angle of the tilt plateto a tilt angle according to the correction amount C. Then, the installing toolswitched to the free state is pressed against the tilt plateto make the chip holding surfaceconform the tilt plate, and then the installing toolis switched to the fixed state. When the correction of the holding surface adjusting mechanismis completed, the process returns to step S, and the chipis installed on the new substrate. Then, finally, when the installing of the chipis completed for all the necessary substrates(No in S), the manufacturing process is completed.

In this way, in the present example, the tilt angle of the installed chipwith respect to the installing surfaceis measured, and the measurement result is fed back to the next and subsequent installing operations. As a result, the degree of parallelization of the chipwith respect to the installing surfacecan be further improved.

Next, the calculation of the correction amount C will be described. A calculation procedure of the correction amount C is not particularly limited as long as the detection tilt angle Sd in the next substrateapproaches zero. In the present example, a basic tilt angle Ss is calculated by removing an influence of the correction of the holding surface tilt angle Sb from each of the plurality of detection tilt angles Sd obtained for the plurality of substrates, and a calculation policy of the correction amount C is changed according to a change tendency of the basic tilt angle Ss between the substrates.

Prior to the detailed description of the calculation of the correction amount C, parameters used in the calculation of the correction amount C will be described with reference to.is a view showing examples of changes of various parameters when the installing of the chip, the measuring of the detection tilt angle Sd, the correction of the holding surface tilt angle Sb are repeatedly executed with respect to four substratesaccording to the flow of. Even in a case in which the holding surface tilt angle Sb is kept constant, the degree of parallelization of the chipwith respect to the installing surfacevaries between the substrates. There are various causes of the variation in the degree of parallelization between the substrates, such as a change in temperature or load, a correction error, and a variation in quality of the substrate, but in, these are collectively expressed as a tilt of the installing surfaceof the substrate. Then, the tilt of the installing surfaceof the substrateinis a tilt angle obtained by removing the influence of the correction from the detection tilt angle Sd and is a detection tilt angle Sd that can be obtained in a case in which the correction of the holding surface tilt angle Sb is not performed at all. In the following, the detection tilt angle (the tilt angle of the installing surfacein) that can be obtained in a case in which this correction is not performed is the “basic tilt angle Ss.”

In a case in which the detection tilt angle Sd, the basic tilt angle Ss, the holding surface tilt angle Sb, and the correction amount C of an n-th substrateare set to Sd [n], Ss [n], Sb [n], and C [n], respectively, the n-th holding surface tilt angle Sb [n] and the n-th basic tilt angle Ss [n] can be expressed by the following equation 1 and equation 2, respectively.1]+  equation 1  equation 2

In the example of, since the correction of the holding surface tilt angle Sb has never been performed at a step of a first substrate, the correction amount C[1]=0°, and the holding surface tilt angle Sb[1]=0°. In this case, in a case in which it can be measured that the detection tilt angle Sd[1]=−5°, it can be calculated that the basic tilt angle Ss[1]=Sb[1]−Sd[1]=+5°.

To cancel the detection tilt angle Sd [1] of the first substrate, it is assumed that the correction amount C[2]=−Sd[1]=+5° for a second substrate. In this case, in the second substrate, the holding surface tilt angle Sb [2] is that Sb[2]=Sb[1]+C[2]=+5°. Then, in a case in which the detection tilt angle Sd [2] of the second substrate=−5°, the basic tilt angle Ss [2] of the second substratecan be calculated as Ss[2]=Sb[2]−Sd[2]=+10°. Similarly, for third and subsequent substrates, the basic tilt angle Ss [n] can be calculated on the basis of the detection tilt angle Sd [n].

The controllersequentially calculates the basic tilt angles Ss according to equations 1 and 2, identifies a change tendency of the basic tilt angle Ss between the substrates, and calculates the correction amount C by a procedure suitable for the change tendency. In the present example, the change tendency is divided into three types: a “small variation,” a “regularity,” and a “random change.”are diagrams for explaining these three types of change tendencies. In each figure, a horizontal axis represents the number of samples n of the substrate, and a vertical axis represents the basic tilt angle Ss of the n-th substrate.

As shown in, in a case in which the variation of a plurality of basic tilt angles Ss is small, it can be said that the causes of the tilt of the chipwith respect to the installing surface, for example, the temperature change, the quality of the substrate, or the like are generally stable. Therefore, in this case, the controllercalculates a value to cancel a nearest detection tilt angle Sd [n] as a correction amount C [n+1] of the next substrate. That is, the controllerperforms an operation of C[n+1]=−Sd[n]. For the evaluation of a variation, for example, a variance or a standard deviation is used. Therefore, for example, the controllerobtains a standard deviation of the plurality of basic tilt angles Ss, and in a case in which the standard deviation is equal to or less than a predetermined allowable value, the correction amount C is calculated as C[n+1]=−Sd[n].

On the other hand, as shown in, in a case in which the basic tilt angle Ss changes with a predetermined regularity, it can be inferred that the causes of the tilt of the chipwith respect to the installing surfacealso change with a regularity. Therefore, in this case, the controllerobtains a basic tilt angle Ss[n+1] of the next substrateaccording to this regularity and calculates a value to cancel the basic tilt angle Ss[n+1] as a correction amount C of the next substrate. For example, in a case in which a and b are constants, a case in which the basic tilt angle Ss changes according to a linear function of “Ss[n]=a×n+b” is considered. In this case, the basic tilt angle Ss[n+1] of the next substratecan be inferred to be Ss[n+1]=a×(n+1)+b.

Further, a detection tilt angle Sd[n+1] of the next substrateis expressed by the following equation 3. Then, since a correction amount C[n+1] of the next substrateis a value that makes the detection tilt angle Sd[n+1] zero, it can be obtained by equation 4.1]=1]−1]  equation 31]=1]−  equation 4

First, for example, an approximate curve Ac of the plurality of basic tilt angles Ss is obtained, and then whether or not the change is made with a regularity may be determined on the basis of a degree of approximation between the approximate curve Ac and the plurality of basic tilt angle Ss. Here, the approximate curve Ac is not limited to the linear function as described above and may be a quadratic function, an exponential function, a logarithmic function, or the like. Further, the degree of approximation may be expressed by, for example, a mean square error between the approximate curve Ac and the plurality of basic tilt angles Ss. That is, the controllermay determine that the basic tilt angle Ss changes regularly in a case in which the mean square error of the plurality of basic tilt angles Ss with respect to the approximate curve Ac is equal to or less than a predetermined allowable value.

Next, as shown in, a case in which the basic tilt angle Ss changes randomly without a regularity, that is, a case in which the mean square error of the plurality of basic tilt angles Ss with respect to the approximate curve Ac exceeds an allowable value will be described. In this case, it can be inferred that the causes of the tilt of the chipwith respect to the installing surfacealso change randomly. In this case, the controllerestimates a representative value of the plurality of basic tilt angles Ss as the basic tilt angle Ss[n+1] of the next substrateand calculates a value to cancel the basic tilt angle Ss[n+1] as the correction amount C[n+1] of the next substrate. Here, the representative value is, for example, a mean, a median, or a mode. If the controllerestimates the representative value of the plurality of basic tilt angles Ss as the basic tilt angle Ss[n+1] of the next substrate, the controllerapplies the basic tilt angles Ss[n+1] to equation 4 to calculate the next correction amount C[n+1].

is a flowchart showing a detailed flow of a correction amount calculation step (step Sof). In a case in which the correction amount C is calculated, as described above, first, the basic tilt angles Ss of the past N substratesare calculated (S). If the basic tilt angles Ss of the past N substrates can be calculated, then the variation, for example, the variance or the standard deviation of the basic tilt angles Ss of the past N substrates is calculated (S). In a case in which the variation of the basic tilt angles Ss is small, for example, in a case in which the standard deviation is less than or equal to a specified allowable value (Yes in S), the controllercalculates a value to cancel a nearest detection tilt angle Sd[n] as a correction amount C[n+1] of the next substrate(S).

On the other hand, in a case in which the variation of the basic tilt angles Ss of N substrates is large (No in S), the controllerobtains an approximate curve Ac of the basic tilt angles Ss of the N substrates (S). The approximate curve Ac obtained here may be any of a linear function, a quadratic function, an exponential function, and a logarithmic function. Further, the approximate curve Ac obtained here is not limited to one type and may be a plurality of types.

If the approximate curve Ac can be calculated, then the controllercompares the approximate curve Ac with the basic tilt angles Ss for N substrates (S). As a result of the comparison, in a case in which the degree of approximation between the approximate curve Ac and the basic tilt angles Ss is large (Yes in S), for example, in a case in which the mean square error between the approximate curve Ac and the basic tilt angles Ss is less than or equal to the allowable value, the controllerobtains the next basic tilt angle Ss[n+1] on the basis of the approximate curve Ac (S). In a case in which a plurality of types of approximate curves Ac are obtained in step S, Ss[n+1] may be obtained on the basis of an approximate curve Ac having a maximum degree of approximation among the plurality of approximate curves Ac. On the other hand, in a case in which the degree of approximation between the approximate curve Ac and the basic tilt angles Ss is small (No in S), the controllersets the representative value of the basic tilt angles Ss of the past N substrates, for example, a mean or the like as the basic tilt angle Ss[n+1] of the next substrate(S). Then, if the basic tilt angle Ss[n+1] of the next substrateis obtained, the basic tilt angle Ss[n+1] is applied to equation 4 and the correction amount C[n+1] of the next substrateis calculated (S).